drivers/s390/cio/cio.c

   1 /*
   2  *  drivers/s390/cio/cio.c
   3  *   S/390 common I/O routines -- low level i/o calls
   4  *
   5  *    Copyright (C) IBM Corp. 1999,2006
   6  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Arnd Bergmann (arndb@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/device.h>
  16 #include <linux/kernel_stat.h>
  17 #include <linux/interrupt.h>
  18 #include <asm/cio.h>
  19 #include <asm/delay.h>
  20 #include <asm/irq.h>
  21 #include <asm/irq_regs.h>
  22 #include <asm/setup.h>
  23 #include <asm/reset.h>
  24 #include <asm/ipl.h>
  25 #include <asm/chpid.h>
  26 #include "airq.h"
  27 #include "cio.h"
  28 #include "css.h"
  29 #include "chsc.h"
  30 #include "ioasm.h"
  31 #include "blacklist.h"
  32 #include "cio_debug.h"
  33 #include "chp.h"
  34 #include "../s390mach.h"
  35
  36 debug_info_t *cio_debug_msg_id;
  37 debug_info_t *cio_debug_trace_id;
  38 debug_info_t *cio_debug_crw_id;
  39
  40 int cio_show_msg;
  41
  42 static int __init
  43 cio_setup (char *parm)
  44 {
  45         if (!strcmp (parm, "yes"))
  46                 cio_show_msg = 1;
  47         else if (!strcmp (parm, "no"))
  48                 cio_show_msg = 0;
  49         else
  50                 printk(KERN_ERR "cio: cio_setup: "
  51                        "invalid cio_msg parameter '%s'", parm);
  52         return 1;
  53 }
  54
  55 __setup ("cio_msg=", cio_setup);
  56
  57 /*
  58  * Function: cio_debug_init
  59  * Initializes three debug logs (under /proc/s390dbf) for common I/O:
  60  * - cio_msg logs the messages which are printk'ed when CONFIG_DEBUG_IO is on
  61  * - cio_trace logs the calling of different functions
  62  * - cio_crw logs the messages which are printk'ed when CONFIG_DEBUG_CRW is on
  63  * debug levels depend on CONFIG_DEBUG_IO resp. CONFIG_DEBUG_CRW
  64  */
  65 static int __init
  66 cio_debug_init (void)
  67 {
  68         cio_debug_msg_id = debug_register ("cio_msg", 16, 4, 16*sizeof (long));
  69         if (!cio_debug_msg_id)
  70                 goto out_unregister;
  71         debug_register_view (cio_debug_msg_id, &debug_sprintf_view);
  72         debug_set_level (cio_debug_msg_id, 2);
  73         cio_debug_trace_id = debug_register ("cio_trace", 16, 4, 16);
  74         if (!cio_debug_trace_id)
  75                 goto out_unregister;
  76         debug_register_view (cio_debug_trace_id, &debug_hex_ascii_view);
  77         debug_set_level (cio_debug_trace_id, 2);
  78         cio_debug_crw_id = debug_register ("cio_crw", 4, 4, 16*sizeof (long));
  79         if (!cio_debug_crw_id)
  80                 goto out_unregister;
  81         debug_register_view (cio_debug_crw_id, &debug_sprintf_view);
  82         debug_set_level (cio_debug_crw_id, 2);
  83         return 0;
  84
  85 out_unregister:
  86         if (cio_debug_msg_id)
  87                 debug_unregister (cio_debug_msg_id);
  88         if (cio_debug_trace_id)
  89                 debug_unregister (cio_debug_trace_id);
  90         if (cio_debug_crw_id)
  91                 debug_unregister (cio_debug_crw_id);
  92         printk(KERN_WARNING"cio: could not initialize debugging\n");
  93         return -1;
  94 }
  95
  96 arch_initcall (cio_debug_init);
  97
  98 int
  99 cio_set_options (struct subchannel *sch, int flags)
 100 {
 101        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
 102        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
 103        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
 104        return 0;
 105 }
 106
 107 /* FIXME: who wants to use this? */
 108 int
 109 cio_get_options (struct subchannel *sch)
 110 {
 111        int flags;
 112
 113        flags = 0;
 114        if (sch->options.suspend)
 115                 flags |= DOIO_ALLOW_SUSPEND;
 116        if (sch->options.prefetch)
 117                 flags |= DOIO_DENY_PREFETCH;
 118        if (sch->options.inter)
 119                 flags |= DOIO_SUPPRESS_INTER;
 120        return flags;
 121 }
 122
 123 /*
 124  * Use tpi to get a pending interrupt, call the interrupt handler and
 125  * return a pointer to the subchannel structure.
 126  */
 127 static int
 128 cio_tpi(void)
 129 {
 130         struct tpi_info *tpi_info;
 131         struct subchannel *sch;
 132         struct irb *irb;
 133
 134         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 135         if (tpi (NULL) != 1)
 136                 return 0;
 137         irb = (struct irb *) __LC_IRB;
 138         /* Store interrupt response block to lowcore. */
 139         if (tsch (tpi_info->schid, irb) != 0)
 140                 /* Not status pending or not operational. */
 141                 return 1;
 142         sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 143         if (!sch)
 144                 return 1;
 145         local_bh_disable();
 146         irq_enter ();
 147         spin_lock(sch->lock);
 148         memcpy (&sch->schib.scsw, &irb->scsw, sizeof (struct scsw));
 149         if (sch->driver && sch->driver->irq)
 150                 sch->driver->irq(&sch->dev);
 151         spin_unlock(sch->lock);
 152         irq_exit ();
 153         _local_bh_enable();
 154         return 1;
 155 }
 156
 157 static int
 158 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 159 {
 160         char dbf_text[15];
 161
 162         if (lpm != 0)
 163                 sch->lpm &= ~lpm;
 164         else
 165                 sch->lpm = 0;
 166
 167         stsch (sch->schid, &sch->schib);
 168
 169         CIO_MSG_EVENT(0, "cio_start: 'not oper' status for "
 170                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 171                       sch->schid.sch_no);
 172         sprintf(dbf_text, "no%s", sch->dev.bus_id);
 173         CIO_TRACE_EVENT(0, dbf_text);
 174         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 175
 176         return (sch->lpm ? -EACCES : -ENODEV);
 177 }
 178
 179 int
 180 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 181                struct ccw1 * cpa,       /* logical channel prog addr */
 182                __u8 lpm,                /* logical path mask */
 183                __u8 key)                /* storage key */
 184 {
 185         char dbf_txt[15];
 186         int ccode;
 187
 188         CIO_TRACE_EVENT (4, "stIO");
 189         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 190
 191         /* sch is always under 2G. */
 192         sch->orb.intparm = (__u32)(unsigned long)sch;
 193         sch->orb.fmt = 1;
 194
 195         sch->orb.pfch = sch->options.prefetch == 0;
 196         sch->orb.spnd = sch->options.suspend;
 197         sch->orb.ssic = sch->options.suspend && sch->options.inter;
 198         sch->orb.lpm = (lpm != 0) ? lpm : sch->lpm;
 199 #ifdef CONFIG_64BIT
 200         /*
 201          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 202          */
 203         sch->orb.c64 = 1;
 204         sch->orb.i2k = 0;
 205 #endif
 206         sch->orb.key = key >> 4;
 207         /* issue "Start Subchannel" */
 208         sch->orb.cpa = (__u32) __pa (cpa);
 209         ccode = ssch (sch->schid, &sch->orb);
 210
 211         /* process condition code */
 212         sprintf (dbf_txt, "ccode:%d", ccode);
 213         CIO_TRACE_EVENT (4, dbf_txt);
 214
 215         switch (ccode) {
 216         case 0:
 217                 /*
 218                  * initialize device status information
 219                  */
 220                 sch->schib.scsw.actl |= SCSW_ACTL_START_PEND;
 221                 return 0;
 222         case 1:         /* status pending */
 223         case 2:         /* busy */
 224                 return -EBUSY;
 225         default:                /* device/path not operational */
 226                 return cio_start_handle_notoper(sch, lpm);
 227         }
 228 }
 229
 230 int
 231 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 232 {
 233         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 234 }
 235
 236 /*
 237  * resume suspended I/O operation
 238  */
 239 int
 240 cio_resume (struct subchannel *sch)
 241 {
 242         char dbf_txt[15];
 243         int ccode;
 244
 245         CIO_TRACE_EVENT (4, "resIO");
 246         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 247
 248         ccode = rsch (sch->schid);
 249
 250         sprintf (dbf_txt, "ccode:%d", ccode);
 251         CIO_TRACE_EVENT (4, dbf_txt);
 252
 253         switch (ccode) {
 254         case 0:
 255                 sch->schib.scsw.actl |= SCSW_ACTL_RESUME_PEND;
 256                 return 0;
 257         case 1:
 258                 return -EBUSY;
 259         case 2:
 260                 return -EINVAL;
 261         default:
 262                 /*
 263                  * useless to wait for request completion
 264                  *  as device is no longer operational !
 265                  */
 266                 return -ENODEV;
 267         }
 268 }
 269
 270 /*
 271  * halt I/O operation
 272  */
 273 int
 274 cio_halt(struct subchannel *sch)
 275 {
 276         char dbf_txt[15];
 277         int ccode;
 278
 279         if (!sch)
 280                 return -ENODEV;
 281
 282         CIO_TRACE_EVENT (2, "haltIO");
 283         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 284
 285         /*
 286          * Issue "Halt subchannel" and process condition code
 287          */
 288         ccode = hsch (sch->schid);
 289
 290         sprintf (dbf_txt, "ccode:%d", ccode);
 291         CIO_TRACE_EVENT (2, dbf_txt);
 292
 293         switch (ccode) {
 294         case 0:
 295                 sch->schib.scsw.actl |= SCSW_ACTL_HALT_PEND;
 296                 return 0;
 297         case 1:         /* status pending */
 298         case 2:         /* busy */
 299                 return -EBUSY;
 300         default:                /* device not operational */
 301                 return -ENODEV;
 302         }
 303 }
 304
 305 /*
 306  * Clear I/O operation
 307  */
 308 int
 309 cio_clear(struct subchannel *sch)
 310 {
 311         char dbf_txt[15];
 312         int ccode;
 313
 314         if (!sch)
 315                 return -ENODEV;
 316
 317         CIO_TRACE_EVENT (2, "clearIO");
 318         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 319
 320         /*
 321          * Issue "Clear subchannel" and process condition code
 322          */
 323         ccode = csch (sch->schid);
 324
 325         sprintf (dbf_txt, "ccode:%d", ccode);
 326         CIO_TRACE_EVENT (2, dbf_txt);
 327
 328         switch (ccode) {
 329         case 0:
 330                 sch->schib.scsw.actl |= SCSW_ACTL_CLEAR_PEND;
 331                 return 0;
 332         default:                /* device not operational */
 333                 return -ENODEV;
 334         }
 335 }
 336
 337 /*
 338  * Function: cio_cancel
 339  * Issues a "Cancel Subchannel" on the specified subchannel
 340  * Note: We don't need any fancy intparms and flags here
 341  *       since xsch is executed synchronously.
 342  * Only for common I/O internal use as for now.
 343  */
 344 int
 345 cio_cancel (struct subchannel *sch)
 346 {
 347         char dbf_txt[15];
 348         int ccode;
 349
 350         if (!sch)
 351                 return -ENODEV;
 352
 353         CIO_TRACE_EVENT (2, "cancelIO");
 354         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 355
 356         ccode = xsch (sch->schid);
 357
 358         sprintf (dbf_txt, "ccode:%d", ccode);
 359         CIO_TRACE_EVENT (2, dbf_txt);
 360
 361         switch (ccode) {
 362         case 0:         /* success */
 363                 /* Update information in scsw. */
 364                 stsch (sch->schid, &sch->schib);
 365                 return 0;
 366         case 1:         /* status pending */
 367                 return -EBUSY;
 368         case 2:         /* not applicable */
 369                 return -EINVAL;
 370         default:        /* not oper */
 371                 return -ENODEV;
 372         }
 373 }
 374
 375 /*
 376  * Function: cio_modify
 377  * Issues a "Modify Subchannel" on the specified subchannel
 378  */
 379 int
 380 cio_modify (struct subchannel *sch)
 381 {
 382         int ccode, retry, ret;
 383
 384         ret = 0;
 385         for (retry = 0; retry < 5; retry++) {
 386                 ccode = msch_err (sch->schid, &sch->schib);
 387                 if (ccode < 0)  /* -EIO if msch gets a program check. */
 388                         return ccode;
 389                 switch (ccode) {
 390                 case 0: /* successfull */
 391                         return 0;
 392                 case 1: /* status pending */
 393                         return -EBUSY;
 394                 case 2: /* busy */
 395                         udelay (100);   /* allow for recovery */
 396                         ret = -EBUSY;
 397                         break;
 398                 case 3: /* not operational */
 399                         return -ENODEV;
 400                 }
 401         }
 402         return ret;
 403 }
 404
 405 /*
 406  * Enable subchannel.
 407  */
 408 int
 409 cio_enable_subchannel (struct subchannel *sch, unsigned int isc)
 410 {
 411         char dbf_txt[15];
 412         int ccode;
 413         int retry;
 414         int ret;
 415
 416         CIO_TRACE_EVENT (2, "ensch");
 417         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 418
 419         if (sch_is_pseudo_sch(sch))
 420                 return -EINVAL;
 421         ccode = stsch (sch->schid, &sch->schib);
 422         if (ccode)
 423                 return -ENODEV;
 424
 425         for (retry = 5, ret = 0; retry > 0; retry--) {
 426                 sch->schib.pmcw.ena = 1;
 427                 sch->schib.pmcw.isc = isc;
 428                 sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
 429                 ret = cio_modify(sch);
 430                 if (ret == -ENODEV)
 431                         break;
 432                 if (ret == -EIO)
 433                         /*
 434                          * Got a program check in cio_modify. Try without
 435                          * the concurrent sense bit the next time.
 436                          */
 437                         sch->schib.pmcw.csense = 0;
 438                 if (ret == 0) {
 439                         stsch (sch->schid, &sch->schib);
 440                         if (sch->schib.pmcw.ena)
 441                                 break;
 442                 }
 443                 if (ret == -EBUSY) {
 444                         struct irb irb;
 445                         if (tsch(sch->schid, &irb) != 0)
 446                                 break;
 447                 }
 448         }
 449         sprintf (dbf_txt, "ret:%d", ret);
 450         CIO_TRACE_EVENT (2, dbf_txt);
 451         return ret;
 452 }
 453
 454 /*
 455  * Disable subchannel.
 456  */
 457 int
 458 cio_disable_subchannel (struct subchannel *sch)
 459 {
 460         char dbf_txt[15];
 461         int ccode;
 462         int retry;
 463         int ret;
 464
 465         CIO_TRACE_EVENT (2, "dissch");
 466         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 467
 468         if (sch_is_pseudo_sch(sch))
 469                 return 0;
 470         ccode = stsch (sch->schid, &sch->schib);
 471         if (ccode == 3)         /* Not operational. */
 472                 return -ENODEV;
 473
 474         if (sch->schib.scsw.actl != 0)
 475                 /*
 476                  * the disable function must not be called while there are
 477                  *  requests pending for completion !
 478                  */
 479                 return -EBUSY;
 480
 481         for (retry = 5, ret = 0; retry > 0; retry--) {
 482                 sch->schib.pmcw.ena = 0;
 483                 ret = cio_modify(sch);
 484                 if (ret == -ENODEV)
 485                         break;
 486                 if (ret == -EBUSY)
 487                         /*
 488                          * The subchannel is busy or status pending.
 489                          * We'll disable when the next interrupt was delivered
 490                          * via the state machine.
 491                          */
 492                         break;
 493                 if (ret == 0) {
 494                         stsch (sch->schid, &sch->schib);
 495                         if (!sch->schib.pmcw.ena)
 496                                 break;
 497                 }
 498         }
 499         sprintf (dbf_txt, "ret:%d", ret);
 500         CIO_TRACE_EVENT (2, dbf_txt);
 501         return ret;
 502 }
 503
 504 int cio_create_sch_lock(struct subchannel *sch)
 505 {
 506         sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
 507         if (!sch->lock)
 508                 return -ENOMEM;
 509         spin_lock_init(sch->lock);
 510         return 0;
 511 }
 512
 513 /*
 514  * cio_validate_subchannel()
 515  *
 516  * Find out subchannel type and initialize struct subchannel.
 517  * Return codes:
 518  *   SUBCHANNEL_TYPE_IO for a normal io subchannel
 519  *   SUBCHANNEL_TYPE_CHSC for a chsc subchannel
 520  *   SUBCHANNEL_TYPE_MESSAGE for a messaging subchannel
 521  *   SUBCHANNEL_TYPE_ADM for a adm(?) subchannel
 522  *   -ENXIO for non-defined subchannels
 523  *   -ENODEV for subchannels with invalid device number or blacklisted devices
 524  */
 525 int
 526 cio_validate_subchannel (struct subchannel *sch, struct subchannel_id schid)
 527 {
 528         char dbf_txt[15];
 529         int ccode;
 530         int err;
 531
 532         sprintf (dbf_txt, "valsch%x", schid.sch_no);
 533         CIO_TRACE_EVENT (4, dbf_txt);
 534
 535         /* Nuke all fields. */
 536         memset(sch, 0, sizeof(struct subchannel));
 537
 538         sch->schid = schid;
 539         if (cio_is_console(schid)) {
 540                 sch->lock = cio_get_console_lock();
 541         } else {
 542                 err = cio_create_sch_lock(sch);
 543                 if (err)
 544                         goto out;
 545         }
 546         mutex_init(&sch->reg_mutex);
 547         /* Set a name for the subchannel */
 548         snprintf (sch->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x", schid.ssid,
 549                   schid.sch_no);
 550
 551         /*
 552          * The first subchannel that is not-operational (ccode==3)
 553          *  indicates that there aren't any more devices available.
 554          * If stsch gets an exception, it means the current subchannel set
 555          *  is not valid.
 556          */
 557         ccode = stsch_err (schid, &sch->schib);
 558         if (ccode) {
 559                 err = (ccode == 3) ? -ENXIO : ccode;
 560                 goto out;
 561         }
 562         /* Copy subchannel type from path management control word. */
 563         sch->st = sch->schib.pmcw.st;
 564
 565         /*
 566          * ... just being curious we check for non I/O subchannels
 567          */
 568         if (sch->st != 0) {
 569                 CIO_DEBUG(KERN_INFO, 0,
 570                           "cio: Subchannel 0.%x.%04x reports "
 571                           "non-I/O subchannel type %04X\n",
 572                           sch->schid.ssid, sch->schid.sch_no, sch->st);
 573                 /* We stop here for non-io subchannels. */
 574                 err = sch->st;
 575                 goto out;
 576         }
 577
 578         /* Initialization for io subchannels. */
 579         if (!sch->schib.pmcw.dnv) {
 580                 /* io subchannel but device number is invalid. */
 581                 err = -ENODEV;
 582                 goto out;
 583         }
 584         /* Devno is valid. */
 585         if (is_blacklisted (sch->schid.ssid, sch->schib.pmcw.dev)) {
 586                 /*
 587                  * This device must not be known to Linux. So we simply
 588                  * say that there is no device and return ENODEV.
 589                  */
 590                 CIO_MSG_EVENT(4, "Blacklisted device detected "
 591                               "at devno %04X, subchannel set %x\n",
 592                               sch->schib.pmcw.dev, sch->schid.ssid);
 593                 err = -ENODEV;
 594                 goto out;
 595         }
 596         if (cio_is_console(sch->schid))
 597                 sch->opm = 0xff;
 598         else
 599                 sch->opm = chp_get_sch_opm(sch);
 600         sch->lpm = sch->schib.pmcw.pam & sch->opm;
 601
 602         CIO_DEBUG(KERN_INFO, 0,
 603                   "cio: Detected device %04x on subchannel 0.%x.%04X"
 604                   " - PIM = %02X, PAM = %02X, POM = %02X\n",
 605                   sch->schib.pmcw.dev, sch->schid.ssid,
 606                   sch->schid.sch_no, sch->schib.pmcw.pim,
 607                   sch->schib.pmcw.pam, sch->schib.pmcw.pom);
 608
 609         /*
 610          * We now have to initially ...
 611          *  ... set "interruption subclass"
 612          *  ... enable "concurrent sense"
 613          *  ... enable "multipath mode" if more than one
 614          *        CHPID is available. This is done regardless
 615          *        whether multiple paths are available for us.
 616          */
 617         sch->schib.pmcw.isc = 3;        /* could be smth. else */
 618         sch->schib.pmcw.csense = 1;     /* concurrent sense */
 619         sch->schib.pmcw.ena = 0;
 620         if ((sch->lpm & (sch->lpm - 1)) != 0)
 621                 sch->schib.pmcw.mp = 1; /* multipath mode */
 622         /* clean up possible residual cmf stuff */
 623         sch->schib.pmcw.mme = 0;
 624         sch->schib.pmcw.mbfc = 0;
 625         sch->schib.pmcw.mbi = 0;
 626         sch->schib.mba = 0;
 627         return 0;
 628 out:
 629         if (!cio_is_console(schid))
 630                 kfree(sch->lock);
 631         sch->lock = NULL;
 632         return err;
 633 }
 634
 635 /*
 636  * do_IRQ() handles all normal I/O device IRQ's (the special
 637  *          SMP cross-CPU interrupts have their own specific
 638  *          handlers).
 639  *
 640  */
 641 void
 642 do_IRQ (struct pt_regs *regs)
 643 {
 644         struct tpi_info *tpi_info;
 645         struct subchannel *sch;
 646         struct irb *irb;
 647         struct pt_regs *old_regs;
 648
 649         old_regs = set_irq_regs(regs);
 650         irq_enter();
 651         asm volatile ("mc 0,0");
 652         if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
 653                 /**
 654                  * Make sure that the i/o interrupt did not "overtake"
 655                  * the last HZ timer interrupt.
 656                  */
 657                 account_ticks(S390_lowcore.int_clock);
 658         /*
 659          * Get interrupt information from lowcore
 660          */
 661         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 662         irb = (struct irb *) __LC_IRB;
 663         do {
 664                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 665                 /*
 666                  * Non I/O-subchannel thin interrupts are processed differently
 667                  */
 668                 if (tpi_info->adapter_IO == 1 &&
 669                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 670                         do_adapter_IO();
 671                         continue;
 672                 }
 673                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 674                 if (sch)
 675                         spin_lock(sch->lock);
 676                 /* Store interrupt response block to lowcore. */
 677                 if (tsch (tpi_info->schid, irb) == 0 && sch) {
 678                         /* Keep subchannel information word up to date. */
 679                         memcpy (&sch->schib.scsw, &irb->scsw,
 680                                 sizeof (irb->scsw));
 681                         /* Call interrupt handler if there is one. */
 682                         if (sch->driver && sch->driver->irq)
 683                                 sch->driver->irq(&sch->dev);
 684                 }
 685                 if (sch)
 686                         spin_unlock(sch->lock);
 687                 /*
 688                  * Are more interrupts pending?
 689                  * If so, the tpi instruction will update the lowcore
 690                  * to hold the info for the next interrupt.
 691                  * We don't do this for VM because a tpi drops the cpu
 692                  * out of the sie which costs more cycles than it saves.
 693                  */
 694         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 695         irq_exit();
 696         set_irq_regs(old_regs);
 697 }
 698
 699 #ifdef CONFIG_CCW_CONSOLE
 700 static struct subchannel console_subchannel;
 701 static int console_subchannel_in_use;
 702
 703 /*
 704  * busy wait for the next interrupt on the console
 705  */
 706 void
 707 wait_cons_dev (void)
 708 {
 709         unsigned long cr6      __attribute__ ((aligned (8)));
 710         unsigned long save_cr6 __attribute__ ((aligned (8)));
 711
 712         /*
 713          * before entering the spinlock we may already have
 714          * processed the interrupt on a different CPU...
 715          */
 716         if (!console_subchannel_in_use)
 717                 return;
 718
 719         /* disable all but isc 7 (console device) */
 720         __ctl_store (save_cr6, 6, 6);
 721         cr6 = 0x01000000;
 722         __ctl_load (cr6, 6, 6);
 723
 724         do {
 725                 spin_unlock(console_subchannel.lock);
 726                 if (!cio_tpi())
 727                         cpu_relax();
 728                 spin_lock(console_subchannel.lock);
 729         } while (console_subchannel.schib.scsw.actl != 0);
 730         /*
 731          * restore previous isc value
 732          */
 733         __ctl_load (save_cr6, 6, 6);
 734 }
 735
 736 static int
 737 cio_test_for_console(struct subchannel_id schid, void *data)
 738 {
 739         if (stsch_err(schid, &console_subchannel.schib) != 0)
 740                 return -ENXIO;
 741         if (console_subchannel.schib.pmcw.dnv &&
 742             console_subchannel.schib.pmcw.dev ==
 743             console_devno) {
 744                 console_irq = schid.sch_no;
 745                 return 1; /* found */
 746         }
 747         return 0;
 748 }
 749
 750
 751 static int
 752 cio_get_console_sch_no(void)
 753 {
 754         struct subchannel_id schid;
 755
 756         init_subchannel_id(&schid);
 757         if (console_irq != -1) {
 758                 /* VM provided us with the irq number of the console. */
 759                 schid.sch_no = console_irq;
 760                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 761                     !console_subchannel.schib.pmcw.dnv)
 762                         return -1;
 763                 console_devno = console_subchannel.schib.pmcw.dev;
 764         } else if (console_devno != -1) {
 765                 /* At least the console device number is known. */
 766                 for_each_subchannel(cio_test_for_console, NULL);
 767                 if (console_irq == -1)
 768                         return -1;
 769         } else {
 770                 /* unlike in 2.4, we cannot autoprobe here, since
 771                  * the channel subsystem is not fully initialized.
 772                  * With some luck, the HWC console can take over */
 773                 printk(KERN_WARNING "cio: No ccw console found!\n");
 774                 return -1;
 775         }
 776         return console_irq;
 777 }
 778
 779 struct subchannel *
 780 cio_probe_console(void)
 781 {
 782         int sch_no, ret;
 783         struct subchannel_id schid;
 784
 785         if (xchg(&console_subchannel_in_use, 1) != 0)
 786                 return ERR_PTR(-EBUSY);
 787         sch_no = cio_get_console_sch_no();
 788         if (sch_no == -1) {
 789                 console_subchannel_in_use = 0;
 790                 return ERR_PTR(-ENODEV);
 791         }
 792         memset(&console_subchannel, 0, sizeof(struct subchannel));
 793         init_subchannel_id(&schid);
 794         schid.sch_no = sch_no;
 795         ret = cio_validate_subchannel(&console_subchannel, schid);
 796         if (ret) {
 797                 console_subchannel_in_use = 0;
 798                 return ERR_PTR(-ENODEV);
 799         }
 800
 801         /*
 802          * enable console I/O-interrupt subclass 7
 803          */
 804         ctl_set_bit(6, 24);
 805         console_subchannel.schib.pmcw.isc = 7;
 806         console_subchannel.schib.pmcw.intparm =
 807                 (__u32)(unsigned long)&console_subchannel;
 808         ret = cio_modify(&console_subchannel);
 809         if (ret) {
 810                 console_subchannel_in_use = 0;
 811                 return ERR_PTR(ret);
 812         }
 813         return &console_subchannel;
 814 }
 815
 816 void
 817 cio_release_console(void)
 818 {
 819         console_subchannel.schib.pmcw.intparm = 0;
 820         cio_modify(&console_subchannel);
 821         ctl_clear_bit(6, 24);
 822         console_subchannel_in_use = 0;
 823 }
 824
 825 /* Bah... hack to catch console special sausages. */
 826 int
 827 cio_is_console(struct subchannel_id schid)
 828 {
 829         if (!console_subchannel_in_use)
 830                 return 0;
 831         return schid_equal(&schid, &console_subchannel.schid);
 832 }
 833
 834 struct subchannel *
 835 cio_get_console_subchannel(void)
 836 {
 837         if (!console_subchannel_in_use)
 838                 return NULL;
 839         return &console_subchannel;
 840 }
 841
 842 #endif
 843 static int
 844 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 845 {
 846         int retry, cc;
 847
 848         cc = 0;
 849         for (retry=0;retry<3;retry++) {
 850                 schib->pmcw.ena = 0;
 851                 cc = msch(schid, schib);
 852                 if (cc)
 853                         return (cc==3?-ENODEV:-EBUSY);
 854                 stsch(schid, schib);
 855                 if (!schib->pmcw.ena)
 856                         return 0;
 857         }
 858         return -EBUSY; /* uhm... */
 859 }
 860
 861 /* we can't use the normal udelay here, since it enables external interrupts */
 862
 863 static void udelay_reset(unsigned long usecs)
 864 {
 865         uint64_t start_cc, end_cc;
 866
 867         asm volatile ("STCK %0" : "=m" (start_cc));
 868         do {
 869                 cpu_relax();
 870                 asm volatile ("STCK %0" : "=m" (end_cc));
 871         } while (((end_cc - start_cc)/4096) < usecs);
 872 }
 873
 874 static int
 875 __clear_subchannel_easy(struct subchannel_id schid)
 876 {
 877         int retry;
 878
 879         if (csch(schid))
 880                 return -ENODEV;
 881         for (retry=0;retry<20;retry++) {
 882                 struct tpi_info ti;
 883
 884                 if (tpi(&ti)) {
 885                         tsch(ti.schid, (struct irb *)__LC_IRB);
 886                         if (schid_equal(&ti.schid, &schid))
 887                                 return 0;
 888                 }
 889                 udelay_reset(100);
 890         }
 891         return -EBUSY;
 892 }
 893
 894 static int pgm_check_occured;
 895
 896 static void cio_reset_pgm_check_handler(void)
 897 {
 898         pgm_check_occured = 1;
 899 }
 900
 901 static int stsch_reset(struct subchannel_id schid, volatile struct schib *addr)
 902 {
 903         int rc;
 904
 905         pgm_check_occured = 0;
 906         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 907         rc = stsch(schid, addr);
 908         s390_base_pgm_handler_fn = NULL;
 909
 910         /* The program check handler could have changed pgm_check_occured. */
 911         barrier();
 912
 913         if (pgm_check_occured)
 914                 return -EIO;
 915         else
 916                 return rc;
 917 }
 918
 919 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 920 {
 921         struct schib schib;
 922
 923         if (stsch_reset(schid, &schib))
 924                 return -ENXIO;
 925         if (!schib.pmcw.ena)
 926                 return 0;
 927         switch(__disable_subchannel_easy(schid, &schib)) {
 928         case 0:
 929         case -ENODEV:
 930                 break;
 931         default: /* -EBUSY */
 932                 if (__clear_subchannel_easy(schid))
 933                         break; /* give up... */
 934                 stsch(schid, &schib);
 935                 __disable_subchannel_easy(schid, &schib);
 936         }
 937         return 0;
 938 }
 939
 940 static atomic_t chpid_reset_count;
 941
 942 static void s390_reset_chpids_mcck_handler(void)
 943 {
 944         struct crw crw;
 945         struct mci *mci;
 946
 947         /* Check for pending channel report word. */
 948         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 949         if (!mci->cp)
 950                 return;
 951         /* Process channel report words. */
 952         while (stcrw(&crw) == 0) {
 953                 /* Check for responses to RCHP. */
 954                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 955                         atomic_dec(&chpid_reset_count);
 956         }
 957 }
 958
 959 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 960 static void css_reset(void)
 961 {
 962         int i, ret;
 963         unsigned long long timeout;
 964         struct chp_id chpid;
 965
 966         /* Reset subchannels. */
 967         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 968         /* Reset channel paths. */
 969         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 970         /* Enable channel report machine checks. */
 971         __ctl_set_bit(14, 28);
 972         /* Temporarily reenable machine checks. */
 973         local_mcck_enable();
 974         chp_id_init(&chpid);
 975         for (i = 0; i <= __MAX_CHPID; i++) {
 976                 chpid.id = i;
 977                 ret = rchp(chpid);
 978                 if ((ret == 0) || (ret == 2))
 979                         /*
 980                          * rchp either succeeded, or another rchp is already
 981                          * in progress. In either case, we'll get a crw.
 982                          */
 983                         atomic_inc(&chpid_reset_count);
 984         }
 985         /* Wait for machine check for all channel paths. */
 986         timeout = get_clock() + (RCHP_TIMEOUT << 12);
 987         while (atomic_read(&chpid_reset_count) != 0) {
 988                 if (get_clock() > timeout)
 989                         break;
 990                 cpu_relax();
 991         }
 992         /* Disable machine checks again. */
 993         local_mcck_disable();
 994         /* Disable channel report machine checks. */
 995         __ctl_clear_bit(14, 28);
 996         s390_base_mcck_handler_fn = NULL;
 997 }
 998
 999 static struct reset_call css_reset_call = {
1000         .fn = css_reset,
1001 };
1002
1003 static int __init init_css_reset_call(void)
1004 {
1005         atomic_set(&chpid_reset_count, 0);
1006         register_reset_call(&css_reset_call);
1007         return 0;
1008 }
1009
1010 arch_initcall(init_css_reset_call);
1011
1012 struct sch_match_id {
1013         struct subchannel_id schid;
1014         struct ccw_dev_id devid;
1015         int rc;
1016 };
1017
1018 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1019 {
1020         struct schib schib;
1021         struct sch_match_id *match_id = data;
1022
1023         if (stsch_reset(schid, &schib))
1024                 return -ENXIO;
1025         if (schib.pmcw.dnv &&
1026             (schib.pmcw.dev == match_id->devid.devno) &&
1027             (schid.ssid == match_id->devid.ssid)) {
1028                 match_id->schid = schid;
1029                 match_id->rc = 0;
1030                 return 1;
1031         }
1032         return 0;
1033 }
1034
1035 static int reipl_find_schid(struct ccw_dev_id *devid,
1036                             struct subchannel_id *schid)
1037 {
1038         struct sch_match_id match_id;
1039
1040         match_id.devid = *devid;
1041         match_id.rc = -ENODEV;
1042         for_each_subchannel(__reipl_subchannel_match, &match_id);
1043         if (match_id.rc == 0)
1044                 *schid = match_id.schid;
1045         return match_id.rc;
1046 }
1047
1048 extern void do_reipl_asm(__u32 schid);
1049
1050 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1051 void reipl_ccw_dev(struct ccw_dev_id *devid)
1052 {
1053         struct subchannel_id schid;
1054
1055         s390_reset_system();
1056         if (reipl_find_schid(devid, &schid) != 0)
1057                 panic("IPL Device not found\n");
1058         do_reipl_asm(*((__u32*)&schid));
1059 }
1060
1061 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1062 {
1063         struct subchannel_id schid;
1064         struct schib schib;
1065
1066         schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
1067         if (!schid.one)
1068                 return -ENODEV;
1069         if (stsch(schid, &schib))
1070                 return -ENODEV;
1071         if (!schib.pmcw.dnv)
1072                 return -ENODEV;
1073         iplinfo->devno = schib.pmcw.dev;
1074         iplinfo->is_qdio = schib.pmcw.qf;
1075         return 0;
1076 }